Endometriosis vs. PCOS vs. Adenomyosis: Telling the Conditions Apart

Millions of women worldwide suffer from endometriosis, polycystic ovary syndrome (PCOS), or adenomyosis – three distinct gynecological conditions that can sometimes be tricky to tell apart. Each condition has unique causes and symptoms, yet they also share some overlapping features such as menstrual irregularities or fertility problems.

Understanding the differences (and similarities) is crucial for getting the right diagnosis and treatment. This comparative overview breaks down what sets endometriosis vs. PCOS vs. adenomyosis apart, how they can co-occur, and the latest insights on diagnosis and treatment – all backed by credible medical sources and recent research.

Why Understanding the Difference Matters

Endometriosis, PCOS, and adenomyosis affect millions of people globally and are leading causes of chronic pelvic pain, irregular periods, and infertility. Yet, they are often misunderstood, underdiagnosed, or misdiagnosed. Misunderstanding or overlooking the specifics can delay effective treatment and exacerbate symptoms over time.

Understanding how these conditions differ and relate is key to:

Getting an accurate diagnosis
Choosing appropriate treatment options
Managing long-term health outcomes

What is Endometriosis?

Endometriosis is a chronic, inflammatory condition in which tissue similar to the uterine lining (endometrium) grows outside the uterus. These growths, called lesions or implants, can develop on the ovaries, fallopian tubes, bowel, bladder, and even outside the pelvic cavity.

The hallmark symptom is pelvic pain – often severe – especially during menstrual periods (dysmenorrhea), during or after sex, or when having bowel movements or urinating during menses. Many with endometriosis also experience chronic pelvic pain outside of periods, fatigue, bloating, or pain in the lower back and legs. Another key effect is infertility: an estimated 30–50% of women with endometriosis have difficulty getting pregnant.

In fact, endometriosis is present in about 10% of reproductive-age women globally– roughly 1 in 10 – making it a major women’s health issue. Yet it often goes undiagnosed for years: on average it takes 4–11 years to get a correct diagnosis, and as many as 6 in 10 cases may remain undiagnosed. There is no definitive cure, but treatments can manage symptoms and improve quality of life.

Core Symptoms of Endometriosis:

Chronic pelvic pain (especially during menstruation)
Painful periods (dysmenorrhea)
Pain during or after sex
Painful bowel movements or urination during menstruation
Fatigue
Infertility
Gastrointestinal symptoms (bloating, nausea, diarrhea, or constipation)

Key Facts:

Endometriosis affects approximately 1 in 10 women of reproductive age globally, though it can also affect trans and nonbinary individuals assigned female at birth.
Symptoms can occur as early as adolescence.
Endometriosis is often diagnosed through laparoscopy, a surgical procedure.

For more on endometriosis symptoms and treatment, see our guide: Endometriosis 101.

What is PCOS (Polycystic Ovary Syndrome)?

Polycystic Ovary Syndrome (PCOS) is a hormonal disorder characterized by irregular or absent ovulation and an excess of androgens (male hormones). It’s the most common endocrine disorder affecting individuals with ovaries – affecting up to 15% worldwide, even more common than diabetes in this group.

PCOS is a syndrome, meaning it’s defined by a collection of symptoms related to hormone imbalancenichd.nih.gov. The disorder is characterized by irregular or absent ovulation, excess androgens (male-type hormones), and often multiple small ovarian follicles (misleadingly called “cysts”) on ultrasoundnichd.nih.gov. Because of infrequent ovulation, women with PCOS typically have irregular menstrual cycles – they may go many weeks or months without a period, or have very long, heavy periods when menstruation does occur.

Unlike endometriosis and adenomyosis, PCOS usually does not cause severe pelvic pain during periods. Instead, its signature symptoms are related to hormone imbalance: signs of high androgens such as acne, oily skin, scalp hair thinning, weight gain, and excess hair growth on the face or body (hirsutism).

PCOS is also frequently associated with insulin resistance, so some women develop pre-diabetes or type 2 diabetes over time. Despite the name, not all patients have ovarian cysts, but many have enlarged ovaries with a “polycystic” appearance (many immature follicles). PCOS is a leading cause of infertility because irregular ovulation makes it hard to conceive.

It’s often underdiagnosed – one estimate suggests up to 50% of PCOS cases go undetected – in part because symptoms can vary and overlap with normal pubertal changes. Diagnosis requires assessing multiple factors (menstrual history, blood hormone levels, ultrasound findings) and excluding other conditions.

Core Symptoms of PCOS:

Irregular or absent periods
Acne and oily skin
Excess hair growth (hirsutism), especially on the face, chest, and abdomen
Thinning scalp hair (androgenic alopecia)
Weight gain or difficulty losing weight
Insulin resistance or type 2 diabetes
Polycystic-appearing ovaries on ultrasound (but not required for diagnosis)

Key Facts:

PCOS affects 5% to 15% of individuals of reproductive age, depending on diagnostic criteria.
Diagnosis is typically based on the Rotterdam Criteria, which requires two of the following:
1. Irregular or absent ovulation
2. Signs of high androgen levels (clinical or biochemical)
3. Polycystic ovaries on ultrasound
PCOS increases the risk of metabolic conditions, including insulin resistance, cardiovascular disease, and type 2 diabetes.

What is Adenomyosis?

Adenomyosis occurs when endometrial tissue grows into the muscular wall of the uterus (myometrium). Unlike endometriosis, which exists outside the uterus, adenomyosis is confined to the uterus—but it can still cause significant pain and heavy bleeding.

Adenomyosis is the least talked-about of the three, but it’s increasingly recognized as an important cause of pelvic pain and heavy periods. In adenomyosis, the tissue that normally lines the uterus (endometrium) instead grows deep within the muscular wall of the uterus (the myometrium). In essence, endometrial cells infiltrate the muscle of the uterus. Much like endometriosis, this displaced tissue still behaves normally – thickening and bleeding with each menstrual cycle – but it is trapped in the uterine muscle, leading to an enlarged, boggy uterus and painful, heavy periods.

Classic symptoms include intensely heavy menstrual bleeding (often with clots) and severe cramping pelvic pain during periods. Some women with adenomyosis also have chronic pelvic pain or pain during intercourse. Others notice their lower abdomen enlarging or a persistent “bloated” feeling due to an enlarged uterus (in fact, adenomyosis can double or triple the size of the uterus).

However, not everyone with adenomyosis has symptoms – about one-third of cases are asymptomatic. Historically, adenomyosis was most often diagnosed in women in their 40s who had had children (it used to be called “endometriosis of the older uterus”), and indeed risk is higher in women over 40 and those who’ve given birth. But improved imaging means it’s now being identified in younger women too, especially those in their 30s with unexplained heavy, painful periods.

The true prevalence of adenomyosis is hard to pin down because it often requires microscopic examination to confirm. Estimates have ranged widely – one review noted figures from 5% up to 70% in various studies, with around 20–30% of women having adenomyosis by the time of hysterectomy. In adolescents with severe menstrual pain, studies have found adenomyosis in about 2–5% of cases. Like the other conditions, adenomyosis can impact fertility: if left untreated it may lead to difficulty conceiving or higher risk of miscarriage, since an embryo may struggle to implant in an abnormal uterine lining.

Core Symptoms of Adenomyosis:

Heavy menstrual bleeding (menorrhagia)
Painful periods (dysmenorrhea)
Pelvic pressure or bloating
Pain during sex
Chronic pelvic pain

Key Facts:

Adenomyosis can coexist with endometriosis. In fact, up to 40-60% of people with adenomyosis may also have endometriosis.
It’s more common in people aged 35 and older, especially those who have had children.
Diagnosis is often made via transvaginal ultrasound or MRI, though definitive diagnosis may only occur after hysterectomy.

Symptom Overlap and Co-Occurrence

One of the reasons these conditions are frequently misdiagnosed or missed entirely is that their symptoms often overlap. Here’s a quick breakdown:

Symptom	Endometriosis	PCOS	Adenomyosis
Pelvic Pain	✅	❌	✅
Painful Periods	✅	❌	✅
Heavy Bleeding	✅	✅	✅
Irregular Periods	✅ (less common)	✅	❌
Infertility	✅	✅	✅
Fatigue	✅	✅ (linked to insulin resistance)	✅
GI Symptoms	✅	❌	✅ (less common)
Acne/Excess Hair	❌	✅	❌

Menstrual Pain

Significant pelvic pain is a red flag for endometriosis or adenomyosis, but is not typical in PCOS. Endometriosis classically causes painful menstrual cramps (often starting before bleeding and lasting during the period), sometimes accompanied by lower back or abdominal pain and pain during sex or bowel movements. Adenomyosis also causes severe cramps and a heavy, aching feeling during periods.

In contrast, most PCOS patients do not have unusually painful periods – they may have mild cramps with heavy bleeding, but not the debilitating pain seen in endo or adeno. If a patient’s main complaint is excruciating period pain, doctors will lean toward endometriosis or adenomyosis rather than PCOS.

Bleeding and Period Flow

All three conditions can cause abnormal menstrual bleeding, but in different ways. Heavy menstrual bleeding can occur in endometriosis (especially if lesions affect the uterus or if there’s co-occurring fibroids or adenomyosis) and is a hallmark of adenomyosis. Women with adenomyosis often endure exceptionally heavy, prolonged periods (menorrhagia), sometimes with blood clots, because the uterine muscle is diffusely swollen with embedded tissue.

Endometriosis may cause heavy or irregular bleeding in some cases, or bleeding between periods, although not everyone with endo has heavy periods. Meanwhile, PCOS often presents with the opposite problem – infrequent periods. PCOS patients commonly have oligomenorrhea (cycles longer than 35 days) or even amenorrhea (no period for 3+ months), due to lack of ovulation.

When their uterine lining does shed, it can be quite heavy because it had extra time to build up – leading to episodes of heavy bleeding as well. So, while a heavy period can occur in any of the three conditions, chronic cycle irregularity (skipped or few periods) points strongly to PCOS, and consistently heavy, clotty periods with severe pain points to adenomyosis. Endometriosis may fall somewhere in between – cycles are usually regular, but flow can be heavy or normal; pain tends to be the more distinguishing factor for endo.

Cycle Irregularity

As noted, irregular cycles suggest a hormonal syndrome like PCOS. Women with PCOS often report they went off birth control and then their periods became very erratic or stopped. In endometriosis and adenomyosis, cycles are usually regular (normal hormonal cycling) – the issue is how painful or heavy those cycles are, not that they vanish. If a young woman rarely gets her period and is not pregnant or on contraception, PCOS is usually the first consideration. By contrast, if her periods come like clockwork but are agonizing and heavy, endometriosis or adenomyosis is more likely.

Pelvic Exam Findings

A doctor’s examination can sometimes tell these conditions apart. Adenomyosis often causes an enlarged, tender uterus – on bimanual exam, the uterus may feel diffusely enlarged or boggy (sometimes comparable to a pregnancy at 8–10 weeks size).

In endometriosis, the uterus is typically normal-sized, but the doctor might feel tender nodules in the pelvis or thickening behind the uterus, or notice that organs are somewhat stuck together (signs of pelvic adhesions). In PCOS, the pelvic exam is often normal; ovaries might be slightly enlarged, but usually not enough for a doctor to feel. Only imaging will show the classic polycystic ovaries. So, an enlarged uterus points toward adenomyosis, not PCOS or typical endometriosis.

Hormonal and Other Symptoms

Some symptoms are unique to PCOS and help set it apart. Androgenic symptoms – for example, unwanted hair growth on the face/chest, persistent acne past the teen years, or thinning scalp hair – strongly suggest PCOS and are not caused by endometriosis or adenomyosis. PCOS is also associated with obesity and signs of insulin resistance (such as acanthosis nigricans, a dark velvety discoloration of skin folds) in a significant subset of patients.

Neither endometriosis nor adenomyosis causes these metabolic issues directly (though a woman with endo could coincidentally have insulin resistance, it’s not due to the endo). On the other hand, endometriosis can have systemic effects like fatigue, nausea, or diarrhea around period time, reflecting its inflammatory nature – symptoms not typically seen in PCOS. If a patient has cyclic bowel symptoms or cyclic urinary pain (for example, painful urination during menses), those are classic for endometriosis involvement and would not be explained by PCOS.

Impact on Fertility

All three conditions can impair fertility, but by different mechanisms. If a woman is struggling to conceive, doctors must consider all three as possible contributors (and it could be a combination). PCOS is a leading cause of ovulation-related infertility – because women with PCOS often don’t ovulate regularly, they have fewer chances to get pregnant.

The good news is fertility medications can often induce ovulation in PCOS patients, and many go on to have successful pregnancies with treatment. Endometriosis can cause infertility by a different route: the lesions and resulting scar tissue can damage or block the fallopian tubes, impair the release of eggs, or create a pelvic environment hostile to fertilization and implantation.

In moderate to severe endo, the anatomy of the pelvis may be distorted by adhesions (for instance, ovaries stuck to the pelvic wall), making natural conception harder. Even milder endometriosis may induce inflammation that affects egg and embryo quality or implantation.

Adenomyosis’ effect on fertility has been less publicized until recently, but we now know adenomyosis can reduce fertility and raise miscarriage risk. The disease disrupts the uterine muscle and lining junction, which can interfere with an embryo implanting and growing. Research indicates untreated adenomyosis can indeed lead to infertility or pregnancy loss in some women.

In one clinical review, experts noted that adenomyosis can make it difficult to conceive and is associated with increased risk of miscarriage and preterm birth. In practice, this means that if a woman has known endometriosis and then develops adenomyosis, her fertility challenges may increase. Each condition alone is capable of affecting fertility, but importantly, it is possible to get pregnant with any of these conditions – they simply make it more challenging for some patients. Proper treatment can often improve the odds of conception.

In short, while endometriosis, PCOS, and adenomyosis can all cause “period problems” or fertility issues, the nature of those problems differs.

Learn more in: Endometriosis and Fertility

A handy way to remember: PCOS = absent or irregular periods + male-pattern hair or acne + polycystic ovaries; Endometriosis = normal periods that are extremely painful + possible other pain symptoms (e.g. pain with sex or bowel movements) + maybe infertility; Adenomyosis = regular periods that are extremely heavy and painful + enlarged uterus.

Of course, symptoms vary per individual, and it’s not always cut-and-dried. For example, one can have both endometriosis and adenomyosis, or even PCOS with an unrelated cause of pelvic pain. That’s why medical evaluation is essential. Next, we’ll see how doctors go about diagnosing each condition and distinguishing among them.

Can You Have More Than One Condition at the Same Time?

Yes! One of the complicating factors in women’s health is that these conditions are not mutually exclusive – a person can have more than one of them at the same time. In fact, it’s not unusual for endometriosis and adenomyosis to be found together, and although less common, it’s also possible to have PCOS and endometriosis together (or PCOS and adenomyosis). Co-occurrence can make diagnosis and management even more challenging.

For example:

Studies suggest 10-20% of people with PCOS may also have endometriosis
Adenomyosis and endometriosis coexist in a large percentage of people with chronic pelvic pain.
PCOS and adenomyosis rarely coexist, but it’s not impossible.

Endometriosis and Adenomyosis

These two often go hand-in-hand. Endometriosis occurs outside the uterus and adenomyosis inside the uterine muscle, but they share some common features (both are estrogen-dependent and involve misplaced endometrial tissue). It’s been observed that many women with moderate to severe endometriosis, especially those in their 30s and 40s, also develop adenomyosis. In fact, having endometriosis is considered a risk factor for adenomyosis.

One study noted that adenomyosis was present in up to 20–24% of women with endometriosis who had a hysterectomy. Clinically, if a patient with known endometriosis starts experiencing significantly heavier periods or her uterus enlarges, doctors will suspect that adenomyosis has joined the party.

The co-existence is important to recognize because it might change the treatment approach – for example, an IUD could help adenomyosis even if the endometriosis side still needs surgical management, or vice versa. The possibility of co-occurrence is one reason that women with endo who have persistent symptoms sometimes end up having a hysterectomy; the surgeon may discover widespread adenomyosis contributing to the pain or bleeding.

The bottom line: endometriosis and adenomyosis frequently co-occur, so much so that some researchers consider adenomyosis part of the same spectrum of disorders. If a woman has one, it’s worth being evaluated for the other.

PCOS and Endometriosis

Historically, PCOS and endometriosis were thought to be completely separate entities with contrasting profiles – one characterized by high estrogen (endometriosis) and the other by high androgens and often low progesterone (PCOS). It was even speculated that having one might protect against the other. However, we now know it is quite possible to have PCOS and endometriosis together, though it’s not very common.

About 5–10% of reproductive-age women have either condition, and studies suggest a subset have both. For example, a recent analysis of women undergoing pelvic surgery found that roughly 5% had both endometriosis and PCOS diagnosed, while in a general population sample about 2% had both conditions

Another case-control study found a significant overlap especially in patients who presented with both pelvic pain and infertility – in other words, women with PCOS who also had chronic pelvic pain were more likely to have unsuspected endometriosis identified. Co-occurrence might be somewhat more likely in women of certain ethnic backgrounds or genetic predispositions, according to emerging research.

For patients and clinicians, the overlap of PCOS and endo means that persistent pain in someone known to have PCOS shouldn’t be written off as just PCOS – it warrants evaluation for endometriosis. Conversely, someone with endometriosis who has infrequent periods or signs of androgen excess might actually have both illnesses simultaneously. Treating combined PCOS and endometriosis can be tricky, since therapy for one condition isn’t always ideal for the other (for instance, birth control pills can help both by suppressing endo pain and regulating PCOS cycles, but if fertility is desired, you have to address PCOS ovulation issues and perhaps do surgery for endo).

There is also a delicate hormonal balance to consider: PCOS patients are at risk for endometrial thickening due to anovulation, so having endometriosis on top of that could further complicate uterine health. The key is that doctors must maintain a high index of suspicion for the less obvious condition when one is already diagnosed.

PCOS and Adenomyosis

This particular combination has not been studied as much, but it can occur. A woman in her late 30s, for example, might have long-standing PCOS and then develop adenomyosis as she ages, especially if she had pregnancies (since adenomyosis risk rises after childbirth).

There’s no known direct link between the two, but having PCOS does not immunize someone from getting adenomyosis. If a PCOS patient starts having much heavier, painful periods than before, adenomyosis (or fibroids) could be an explanation beyond just PCOS-related irregular bleeding. In practice, adenomyosis is often found in women in their 40s, and by that time some PCOS symptoms (like very high androgens) might have mellowed, so clinicians might not immediately connect the two. Still, from a patient perspective, one could certainly end up with both and require treatments targeting each.

Why co-occurrence matters

When these conditions coincide, diagnosis is harder and often delayed. Symptoms can blend together – for example, someone with PCOS and endometriosis might have a confusing mix of cycle irregularity and chronic pain. It’s easy for one aspect to be addressed (say, put on birth control for PCOS) while the other (undiagnosed endometriosis) continues to cause issues.

Co-occurrence can also influence treatment choices. Fortunately, some treatments can help both: lifestyle improvements benefit anyone’s overall health; hormonal contraceptives can tame endometriosis and regulate PCOS; and certain surgeries for endo might incidentally biopsy adenomyosis.

But other times, a combined approach is needed (e.g. a PCOS patient may need fertility meds for ovulation and a laparoscopy to clear endo to maximize pregnancy chances). If you have been diagnosed with one of these conditions and still have symptoms that don’t fully fit, it’s worth discussing with your doctor the possibility of an overlapping condition.

Specialists (such as a reproductive endocrinologist or minimally invasive gynecologic surgeon) may be consulted in complex cases to ensure nothing is missed.

How They're Diagnosed

Due to the diagnostic limitations (especially for endometriosis and adenomyosis), many people are dismissed or misdiagnosed for years. That’s why understanding your symptoms and advocating for further investigation is so important.

Distinguishing between endometriosis, PCOS, and adenomyosis often requires a combination of patient history, physical exam, imaging tests, and sometimes surgery or lab tests. Each condition has its own diagnostic pathway:

Condition	Diagnostic Tools
Endometriosis	Laparoscopy (gold standard), ultrasound, MRI
PCOS	Blood tests (hormones), pelvic ultrasound, physical symptoms (Rotterdam Criteria)
Adenomyosis	Transvaginal ultrasound, MRI, histopathology (post-hysterectomy)

Diagnosing Endometriosis

This can be the most challenging diagnosis of the three. Since endometriosis lesions are often small and located deep in the pelvis, imaging tests (ultrasound, MRI) frequently appear normal in endometriosis patients – especially if there are no large cysts. The only definitive way to diagnose endometriosis is via laparoscopy, a minimally invasive surgery to look inside the abdomen and pelvis and biopsy any suspicious lesions. For many years, a saying in gynecology was “no diagnosis without laparoscopy.”

Today, experienced doctors can often make a clinical diagnosis based on a pattern of symptoms and by ruling out other causes. But still, the gold standard is identifying the lesions surgically. This need for surgery contributes to the long diagnostic delays. On average, it takes many years and consultations for a woman’s pelvic pain to be recognized as endometriosis.

Part of the issue is that symptoms can overlap with other conditions (like fibroids or even irritable bowel syndrome), and many young women are told painful periods are “normal.” Advances are being made – specialized ultrasound techniques and MRI can now detect deep endometriosis or ovarian endometriomas (chocolate cysts) in many cases, and researchers are hunting for noninvasive biomarkers – but as of 2025, there is still no simple blood test for endo. Doctors will typically do a pelvic exam (which may find tenderness or nodules), an ultrasound to check for ovarian cysts or other issues, and perhaps an MRI if deep endometriosis is suspected.

They will also rule out conditions like infections or gastrointestinal disorders. If endometriosis is strongly suspected and symptoms warrant, a diagnostic laparoscopy is often recommended – which not only confirms the diagnosis but can treat the disease at the same time by removing lesions. It’s important to consult a gynecologist who specializes in endometriosis if this condition is suspected, given the complexities in finding it.

Diagnosing PCOS

PCOS is usually diagnosed by a combination of medical history, hormone tests, and ultrasound, following established criteria. The most widely used are the Rotterdam criteria, which say a woman has PCOS if she meets two out of three of the following (after excluding other causes):

Irregular or absent ovulation (manifesting as irregular periods)
Clinical or lab signs of high androgens (e.g. hirsutism, acne or elevated testosterone levels on a blood test)
Polycystic ovaries on ultrasound (generally defined as an ovary with ≥20 small follicles, or ovarian volume >10 mL).

It’s worth noting that an ovarian ultrasound alone is not enough to diagnose PCOS – some women have polycystic-appearing ovaries but normal hormones and regular cycles (in fact, up to 25% of healthy young women might show multifollicular ovaries on an ultrasound).

Therefore, doctors rely on the pattern of symptoms and lab results. Typically, the evaluation for suspected PCOS includes blood tests to check levels of androgens (like testosterone and DHEA-S), ovarian ultrasound, and tests for other related issues (glucose and insulin levels, cholesterol, thyroid function, etc.).

They’ll also rule out other causes of irregular periods or androgen excess – for example, thyroid disorders, elevated prolactin, or an adrenal gland disorder. Unlike endometriosis or adenomyosis, invasive procedures are not needed for PCOS diagnosis. It can usually be made by an endocrinologist or gynecologist based on outpatient tests.

A common scenario is a young woman presenting with very irregular periods and unwanted hair growth; her doctor will suspect PCOS, do the appropriate tests, and make the diagnosis. One challenge: in teens, it can be tricky to diagnose PCOS because normal puberty can cause acne, some irregular cycles, and ovarian cysts. So doctors might observe over time before confirming PCOS in a very young patient. But overall, PCOS diagnosis has become fairly standardized, which helps in getting treatment started sooner.

Diagnosing Adenomyosis

In the past, adenomyosis was usually an “incidental” diagnosis made only when a uterus was removed during surgery and examined under a microscope. Today, however, imaging technology has greatly improved detection of adenomyosis. The condition is often suspected based on symptoms (heavy, painful periods in a woman in her 30s or 40s) and a physical exam finding of an enlarged, tender uterus.

When adenomyosis is suspected, the first-line imaging test is typically a transvaginal ultrasound, where an experienced sonographer can often spot characteristic signs: a diffusely thickened uterine wall, a heterogeneous (patchy) texture in the myometrium, or small cystic areas in the muscle. In some cases, the ultrasound might also show an enlarged uterus that looks “globular.” If ultrasound is inconclusive, an MRI scan of the pelvis can be very helpful; MRI has high accuracy for adenomyosis and can distinguish it from fibroids or other issues by showing subtle thickening and islands of endometrial tissue within the muscle.

Unlike endometriosis, no surgical biopsy is usually needed to diagnose adenomyosis unless there’s concern it could be something else. Doctors may perform an endometrial biopsy (sampling the uterine lining) to rule out cancer or other diseases, but that biopsy won’t definitively show adenomyosis because the issue is in the muscle wall (not typically reached by a standard biopsy).

The definitive confirmation of adenomyosis still comes from pathology – for example, if a patient undergoes a hysterectomy or adenomyomectomy (surgical removal of adenomyosis), the tissue can be examined under a microscope to confirm the diagnosis. In practice, though, if a woman has the typical symptoms and the ultrasound or MRI findings, doctors will treat adenomyosis without requiring proof from surgery. It’s also common for adenomyosis to be discovered along with endometriosis on a laparoscopy or after a hysterectomy done for severe endometriosis; the two often coexist (more on that shortly).

Differentiating adenomyosis from fibroids (benign muscle tumors) is a key part of the diagnostic process, since both can cause heavy, painful periods and an enlarged uterus. Ultrasound or MRI can usually tell diffuse adenomyosis from discrete fibroid nodules, though sometimes the conditions occur together.

In summary, diagnosing these conditions involves different tools: PCOS relies on lab tests and ultrasound, endometriosis often requires laparoscopy (surgery) or at least a specialist’s clinical judgment, and adenomyosis is increasingly diagnosed via imaging (ultrasound/MRI) and clinical signs. It’s not uncommon for women to see multiple doctors over years before getting a clear answer, especially in cases where symptoms overlap or more than one condition is present.

Treatment Pathways for Each Condition

Because the root causes of endometriosis, PCOS, and adenomyosis differ, their treatment approaches also diverge. Each condition requires a tailored strategy, though there is a common theme of hormonal therapies playing a role in managing symptoms for all three.

Here’s a breakdown of how each is treated:

Condition	Treatment Options
Endometriosis	Hormonal therapy, laparoscopic excision, pain management, lifestyle changes
PCOS	Lifestyle changes (diet, exercise), metformin, hormonal birth control, ovulation induction
Adenomyosis	Hormonal IUDs, GnRH analogues, uterine artery embolization, hysterectomy

Treating Endometriosis

There is currently no cure for endometriosis (short of removing or shutting down all estrogen in the body, which isn’t feasible long-term), but there are effective options to control pain and improve fertility. Treatment is often multimodal. For pain relief, nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen are a first step. To slow the growth of endometriosis lesions and reduce pain, doctors commonly use hormonal therapies to suppress menstruation.

These include combination birth control pills, the contraceptive patch or ring, or progestin-only methods like the hormonal IUD or depo-provera shots. More advanced hormonal treatments include GnRH agonists or antagonists (medications that induce a temporary menopausal state and drastically lower estrogen, such as leuprolide or oral GnRH antagonists) – these can be very effective for pain, though they have menopausal side effects and are usually used short-term. A newer class of drugs, oral GnRH antagonists, has made medical suppression of endo easier, and they can be combined with add-back hormones to mitigate side effects.

If medications don’t adequately control symptoms or if there is a desire to improve fertility, surgical treatment is considered. Laparoscopic excision surgery to remove endometriosis lesions and scar tissue is the gold standard surgical approach. Skilled surgeons can often significantly reduce pain and restore more normal anatomy by excising lesions, endometriomas, and adhesions. This can also improve fertility outcomes in some cases.

However, lesions can recur over time, so surgery is sometimes coupled with ongoing medical therapy after recovery. In very severe cases (or when a woman is done with childbearing), a hysterectomy with removal of ovaries might be offered – but this is usually last resort, as it induces menopause and doesn’t always eliminate pain if microscopic lesions remain. Importantly, treatment is personalized: one woman may manage well on birth control pills and occasional painkillers, while another might need multiple surgeries and advanced therapies. There’s growing recognition that a comprehensive approach – including pelvic floor physical therapy, pain management specialists, and even dietary/lifestyle changes – can help alongside medical treatments.

Endometriosis care often requires persistence and often a multi-modal approach that includes non-medical therapies, but many patients do find significant relief with the right combination of therapies.

Treating PCOS

The treatment for PCOS focuses on the patient’s specific symptoms and health goals (for example, is she trying to conceive or mainly concerned with cycle regulation and acne?). Since PCOS is a systemic metabolic and hormonal condition, lifestyle modifications are a foundation: dietary changes and exercise leading to even a modest weight loss (5–10% of body weight if overweight) can help regulate cycles and improve insulin resistance in many women.

Beyond lifestyle, medications are tailored to issues. To regulate menstrual cycles and reduce androgen symptoms in those not trying to get pregnant, the most common treatment is the combined oral contraceptive pill. Birth control pills provide regular progestin exposure to the uterine lining (protecting against endometrial thickening from too many anovulatory cycles) and also increase sex-hormone binding globulin, which lowers free testosterone levels – thereby improving acne and hirsutism over time.

An alternative for cycle regulation is a progestin-only method or simply taking a course of progestin (like medroxyprogesterone) periodically to induce a withdrawal bleed and protect the uterus. For hirsutism that doesn’t improve enough on the pill, doctors may add an anti-androgen medication such as spironolactone (which can reduce hair growth and acne).

It’s important to use contraception when on anti-androgens, since they can cause birth defects if a woman gets pregnant. For metabolic aspects, if insulin resistance or pre-diabetes is present, metformin (an insulin-sensitizing drug) is often prescribed. Metformin can help restore more regular ovulation in some PCOS patients, and it may help with weight management and reducing diabetes risk.

When fertility is the goal, the approach shifts to ovulation induction. First-line for ovulation induction in PCOS is usually an oral medication like letrozole (an aromatase inhibitor) or clomiphene citrate – these drugs stimulate the ovaries to release eggs and have good success rates. Letrozole has in recent years been shown to outperform clomiphene for PCOS fertility, making it a preferred option.

If oral meds don’t work, injectable gonadotropin hormones can be used to induce ovulation, but they carry a higher risk of multiple pregnancy and require careful monitoring. Some women with PCOS ultimately use in vitro fertilization (IVF) if other methods fail, and IVF has the advantage of being very controlled (minimizing high-order multiples).

Alongside these treatments, addressing any lifestyle factors is key: for instance, getting cholesterol and blood pressure under control, treating sleep apnea if present, and looking after mental health (PCOS can be associated with higher rates of anxiety and depression).

In short, PCOS management is often a long-term journey, adjusting treatments as a woman’s life stage changes – e.g., focusing on symptom control in youth and later shifting to fertility, then maybe back to metabolic health after childbearing. The good news is that with the array of therapies available, most PCOS symptoms can be effectively managed or mitigated over time.

Treating Adenomyosis

Management of adenomyosis depends on the severity of symptoms and the patient’s reproductive plans. If symptoms are mild and not disruptive, no treatment is necessary (some women decide to just tolerate heavier periods if pain is manageable). But for those with life-impacting pain or bleeding, there are several options to try before considering major surgery.

Pain management with NSAIDs is a first step to ease menstrual cramps and pelvic pain. To address the heavy bleeding and hormonally driven growth of adenomyosis, hormonal treatments are very effective for many women.

A popular option is the levonorgestrel intrauterine device (IUD) (e.g., Mirena), which releases a small dose of progestin into the uterus. This often significantly reduces menstrual bleeding and can also lessen pain over a few monthsmy.clevelandclinic.org. In fact, the hormonal IUD is now a front-line therapy for adenomyosis in women who wish to preserve fertility, because it’s local (mostly uterine effects) and can be used long term.

Other hormonal therapies include birth control pills (taken continuously to minimize periods) or GnRH analogues (similar to endo treatment, a GnRH agonist can shrink adenomyosis tissue and reduce symptoms, essentially by inducing a temporary menopause; this is usually a short-term measure or a bridge to menopause or surgery).

Another medication used is oral tranexamic acid, a non-hormonal drug taken during periods to reduce bleeding – it can lessen blood loss in adenomyosis patients. If these medical approaches fail to control symptoms, more invasive treatments are considered. One uterus-sparing option is an adenomyomectomy, which is a surgery to excise or remove the adenomyosis-affected portion of the uterus. This can be tricky if the adenomyosis is diffuse, but in some cases (for example, a focal area of adenomyosis) it’s feasible and can relieve symptoms while preserving the uterus.

There are also interventional radiology treatments like uterine artery embolization (UAE) or MRI-guided focused ultrasound, which have shown promise in fibroids and are sometimes used for adenomyosis. These aim to shrink the adenomyosis by cutting off its blood supply or burning it with focused ultrasound; some women experience good relief with these, though results can vary. The definitive cure for adenomyosis is hysterectomy (surgical removal of the uterus).

For women who have completed their families and have severe adenomyosis unresponsive to other treatments, a hysterectomy provides a permanent solution – after the uterus is removed, periods and uterine pain cease, curing adenomyosis. Many patients, however, can avoid hysterectomy by using the medical approaches above, especially if they are still hoping to have children or are far from menopause.

It’s worth noting that adenomyosis symptoms often naturally improve after menopause when estrogen levels decline. So the goal for a 40-year-old patient might be to manage symptoms for a decade until menopause brings relief.

To recap treatment differences in brief:

Endometriosis is managed with pain meds, hormone suppression of periods, and surgical removal of lesions (with hysterectomy as a last resort for refractory cases).
PCOS is managed with lifestyle changes, hormone regulation (birth control or ovulation induction depending on goals), and medications for metabolic and androgen issues. Adenomyosis is managed with pain relief, hormone therapies (especially IUDs or similar to shrink lesions and lighten periods), and if needed, surgical or interventional procedures, with hysterectomy as a definitive cure for those who need it. Often a gynecologist will tailor a plan based on symptom severity and whether future fertility is desired.

Looking Ahead: Getting the Right Diagnosis and Care

Distinguishing endometriosis vs. PCOS vs. adenomyosis is not just a semantic exercise – it has real implications for women’s health. These conditions require different management, and a missed diagnosis can mean years of continued suffering.

If you’re experiencing symptoms like those described – whether it’s the irregular cycles and acne of PCOS, the crippling pelvic pain of endo, the extreme heavy bleeding of adenomyosis, or any combination thereof – it’s crucial to advocate for a thorough evaluation.

That may include seeing a gynecologist who will do imaging for adenomyosis or perform laparoscopy for endometriosis, or an endocrinologist to investigate hormonal imbalances. Sometimes it takes a bit of detective work and persistence to nail down the correct condition.

The good news is that awareness is increasing.

Endometriosis, for instance, has seen a surge of research and public attention in recent years, chipping away at the stigma of “painful periods” and leading to better training of doctors to recognize it. PCOS has a growing support and research network given how common it is, and there’s ongoing research into its genetic causes and long-term health impacts.

Adenomyosis, once called the “enigmatic” condition, is now more frequently diagnosed thanks to MRI and ultrasound improvements, and new treatments are being trialed that might offer alternatives to hysterectomy.

If you have one of these diagnoses, stay informed about your condition – and also about the others, since overlap is possible. It’s entirely feasible for someone to manage more than one reproductive health issue and still lead a healthy life, especially with the help of modern therapies and lifestyle strategies. For instance, a woman with PCOS and endometriosis together might use diet and exercise plus ovulation pills to conceive, and then have laparoscopic surgery to excise endometriosis – addressing both issues step by step.

Or a woman with endometriosis and adenomyosis might use an IUD to calm the adenomyosis and conservative surgery for endo, instead of immediately needing a hysterectomy. Integrated care from a multidisciplinary team (gynecologists, endocrinologists, pain specialists, nutritionists, etc.) is often the optimal approach when symptoms are complex.

In conclusion, while endometriosis, PCOS, and adenomyosis share the common thread of affecting women’s reproductive health and quality of life, they are distinct entities with unique challenges. Knowing the differences can empower patients to ask the right questions and seek appropriate care.

With earlier diagnosis and targeted treatment, women dealing with these conditions can find substantial relief. If you suspect you might be dealing with one of these issues, consider reading more on each (for example, check out our detailed guides on what endometriosis is and how it’s treated, or our PCOS Q&A with an expert from UCSF on managing PCOS and fertility) – and most importantly, consult a healthcare provider who will take your symptoms seriously.

The differences between endometriosis, PCOS, and adenomyosis are clearer than ever, and recognizing those differences is the first step toward effective relief and better health.

References:

World Health Organization (2023). Endometriosis – Key Facts. Endometriosis affects roughly 10% (190 million) of reproductive age women globally ( Endometriosis ).
Mayo Clinic – Adenomyosis: Overview. Adenomyosis occurs when the tissue that normally lines the uterus grows into the muscular wall, causing an enlarged uterus and painful, heavy periods (Adenomyosis - Symptoms & causes - Mayo Clinic).
Medical News Today (2022). Endometriosis vs. PCOS: How to tell the difference. People with endometriosis and PCOS share some symptoms (e.g. heavy bleeding, difficulty getting pregnant), but each condition also has unique symptoms (Endometriosis vs PCOS: How to tell the difference) (Endometriosis vs PCOS: How to tell the difference).
WebMD. Endometriosis vs. Adenomyosis – Inside vs. Outside. In endometriosis, uterine lining tissue grows outside the uterus; in adenomyosis, it grows within the uterine muscle. Both can occur simultaneously (The Difference Between Endometriosis and Adenomyosis) (The Difference Between Endometriosis and Adenomyosis).
Cleveland Clinic – Adenomyosis. Common signs of adenomyosis include heavy or prolonged menstrual bleeding, severe cramping during menstruation, chronic pelvic pain, and painful intercourse (Adenomyosis - Symptoms & causes - Mayo Clinic). Risk factors include being age 40–50, having given birth, prior uterine surgery, or having endometriosis (Adenomyosis: Causes, Symptoms, Diagnosis & Treatment).
Cleveland Clinic – Polycystic Ovary Syndrome (PCOS). PCOS is very common – up to 15% of females of reproductive age have it ( PCOS (Polycystic Ovary Syndrome): Symptoms & Treatment). It’s characterized by irregular periods (from lack of ovulation), signs of high androgens (hirsutism, acne), and polycystic ovaries. It’s a leading cause of female infertility ( PCOS (Polycystic Ovary Syndrome): Symptoms & Treatment).
Medical News Today (2020). The long, painful road to an endometriosis diagnosis. It can take between 4 and 11 years for women to receive the correct diagnosis of endometriosis, and as many as 6 out of every 10 cases may remain undiagnosed (Endometriosis: Its true impact and why it is so hard to diagnose).
Kofinas Fertility Group (2020). PCOS and Endometriosis: Can You Have Both? Both PCOS and endometriosis affect ~5–10% of women each, and some women experience both conditions in their reproductive years (PCOS & Endometriosis: What’s the Difference & Can You Have Both?). PCOS causes anovulation and androgen excess, while endometriosis causes uterine lining tissue to grow outside the uterus (PCOS & Endometriosis: What’s the Difference & Can You Have Both?).
Schliep KC et al. (2023). Co-occurrence of Endometriosis and PCOS. Among women undergoing pelvic surgery, 5% had both endometriosis and PCOS; in a population cohort ~2% had both conditions ( Examining the co-occurrence of endometriosis and polycystic ovarian syndrome - PMC ). This shows that while the overlap is uncommon, it does occur.
Cleveland Clinic – Adenomyosis: Diagnosis & Treatment. Providers suspect adenomyosis based on symptoms and confirm with exams or imaging: an enlarged, tender uterus on pelvic exam, thickened uterine walls on ultrasound or MRI (Adenomyosis: Causes, Symptoms, Diagnosis & Treatment). Hormonal treatments (NSAIDs, birth control pills, IUDs, GnRH analogues) can ease pain and heavy bleeding (Adenomyosis: Causes, Symptoms, Diagnosis & Treatment). Definitive cure is hysterectomy if symptoms are severe (Adenomyosis - Symptoms & causes - Mayo Clinic).
Mayo Clinic – Endometriosis: Symptoms & Causes. Endometriosis is when tissue similar to the endometrium grows outside the uterus, often on ovaries, fallopian tubes, or pelvic lining, causing pelvic pain and potential infertility (Endometriosis - Symptoms and causes - Mayo Clinic) (Endometriosis - Symptoms and causes - Mayo Clinic).
Cleveland Clinic – Adenomyosis and Fertility. Left untreated, adenomyosis can lead to infertility or miscarriage, because an embryo can’t implant properly into an affected uterine lining (Adenomyosis: Causes, Symptoms, Diagnosis & Treatment). This highlights the importance of treatment for women who wish to conceive.